Persistence of viral full-length genomic RNA and replication-associated RNA transcripts and proteins in sheep tissues following acute Crimean-Congo hemorrhagic fever virus infection

Crimean-Congo hemorrhagic fever virus (CCHFV) is a tick-borne RNA virus responsible for a severe hemorrhagic disease in humans. In contrast, the virus appears to cause only a brief viremia without overt clinical signs in animals such as livestock, following which the infection is traditionally assumed to end with complete viral clearance. Here, we challenge this prevailing view by reporting the recovery of full-length viral genomic RNA sequences from tissues of CCHFV-infected sheep long after the resolution of acute viremia. While viral RNA persistence in these tissues was largely characterized by a lack of extensive viral replication, we detected the sporadic presence of replication-associated viral RNA transcripts and viral proteins. These findings suggest that the biology of CCHFV in animals extends well beyond an acute infection. The possibility that the virus can transition into a dormant state, with potential for reactivation to resume gene expression or replication, a phenomenon documented in other RNA viruses, warrants further investigation.